Link for sprinkler-heads.



H. H. BUFF-UM.

UNK FOR SPRINKLER HEADS. APPLICATION FILED ,MAY 22 191B.

PatentedSept. 10,1918

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Specification of Letters Patent. Patented Sept. 10, 1918.

Application filed May 22, 1918. Serial N 0. 235,912.

- To all whom, it may concern:

Be it known that I, HERBERT H. BUFFUM, a citizen of the United States, and resident of Laconia, in the county of Belknap and State of New Hampshire, have invented an Improvement in Links for Sprinkler-Heads, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to devices designed to hold together two parts when sub]ect to normal temperature but which permit the same to separate on an undue rise of temperature. Such devices commonly take the form of links and are used for holding together the valve retaining strut of automatic sprinkler heads.

My invention will best be understood by reference to the following description of the illustrative embodiment thereof shown in the accompanying drawing wherein Figure 1 is a side elevation of a sprinkler head equipped with a link embodying my invention, part being cut away; and

Fig. 2 is a plan view of the parts of the link in separated position, being illustrated as if viewed from the right in Fig. 1.

I have herein disclosed my invention (Fig. 1) as applied to a sprinkler head of that type wherein a valve 3 is held over the outlet of a fitting 5 by means of a strut,

herein denoted generally by the numeral 7, interposed between the valve and an opposed abutment 9. The abutment may, as in the present instance, be formed as a part of a resilient yoke 11.

While the strut may take various forms, I have here illustrated one which comprises two bell crank levers which have the substantially counterpart arms 13 and 15 respectively, pivotally engaging abutment and valve respectively and (herein through mediate means) having a pivotal engagement with each other. The point of bearing between the two arms is out of the line of stress between the two points of bearing on valve and abutment, and thus the two arm cooperatively form a toggle partially broken and the pressure thereon of the valve and abutment tends further to break the toggle. To maintain the same against any water pressure that may be behind the valve and against the spring pressure of the yoke 11, the levers have other arms 17 and 19 extending laterally therefrom which may be connected by a suitable form of thermally releasable link embodying my present invention. The parts hitherto described are not novel to the present application.

In my description of the link here shown I shall use the words upper and lower, inner and outer, in referring to the parts of the link in the position shown in Fig. 1. It will be understood that the words have no definitive significance whatever but are used merely to facilitate description.

The link here shown embodies two plates 21 and 23. The inner plate 21, which may be termed a supporting plate, is herein shown with an opening 25 adjacent one end whereby it may be pivotally engaged with or suspended from the arm 17 of the strut. The lower end of the link is provided with two arms 27 which may terminate in hooked portions 29 which provide a supporting hearing for the plate 23. The lower end of the plate adjacent the bearings 29 is inclined inwardly for a suitable distance, as shown in Fig. 1, thus offsetting the bearing point provided by the hooked portions 29. The plate 23 includes a body portion adapted to be secured in face to face contact with the plate 21 and a lower inclined portion 31 adapted to fit the correspondingly inclined portion of the plate 21 and to be pivotally supported terminally by the hooks 29. The plate 23 may have an opening 33 between the ends thereof whereby it may be engaged with the arm 19 of the strut and herein this opening 33 registers with the slot between the arms 29 which permits the arm 19 of the strut to pass through the inner plate 21 and engage outer plate 23.

The two links assembled in the manner shown in Fig. 1 are secured together in face to face contact by suitable fusible alloy 35 and normally they will hold the parts of the strut in the position shown, the bearing of the plate 23 on the hooks 29 providing a more or less positive resistance. When the alloy is softened by heat, the tension on the link will cause plate 23 to rock clockwise about its bearing on the arms 27, dismantling the link and permitting the strut to be dismembered and so to release the valve 3.

Since the bearing point provided by the this strain is. provided by the strength of the.

alloy joint between the body'portions of the plate above the opening. 33, and since the length of the plate 23 may be varied any reasonable amount the resistance may becontrolled as desired.

It willthus be seenthatI. have provided a simple and convenient link which will be sensitive and which can be conveniently con structed to meet any desired requirements of use.

Having thus described in detail the particular embodiment shown in the accompanying drawing, what I claim as new and desire to secure by Letters Patent is 1. In a device of the class described, a supporting plate having means at one end whereby it may be pivotally suspended'and an offset fulcrum bearing adjacent the other end and a plate secured in face to face con tact therewith and having a portion pivotally engaging said bearing and attachment means remote therefrom.

2. In a'device of the class descrlbed, asupportlng plate havlng means at one end whereby it may be pivotally suspended and an offset fulcrum bearing adjacent theother end and a plate secured in face to face cOntact therewith and having a portion pivotally engagingsaid bearing and attachment Copies of this patentmay be obtained for means remote therefrom and between the ends thereof.

3. In a. device of, the class described,

hooked arms, another plate fitting the first plate and terminally received by the hooks of said arms, saidlatter plate having an opening registeringwith the space between the arms. Y

5. In a device of the class described, two plates having body portions secured in face to face contact' which have engaging means whereby they may be submitted to tension and having portions pivotally engaging one another at a point offset from the planes of the body portions. 7

In testimony whereof I have name to this specification.

HERBERT H. BUFFUM.

signed my.

five cents each, by addressing. the Commissioner. of Patents,

Washington, D. 0; 

